textproduct: Quad Cities

KEY MESSAGES

- A warm front will produce scattered thunderstorms (40-60% coverage) Saturday night into Sunday morning. There is a Marginal Risk (Level 1 out of 5) for severe storms. The primary hazards are hail and gusty winds.

- A pattern change this weekend will bring increasing heat and humidity to the area that is forecast to persist through much of next week. The probability of heat indices exceeding 100 degrees continues to increase (70-90% chance).

SHORT TERM /THROUGH SATURDAY/

Issued at 210 PM CDT Fri Jun 26 2026

Water vapor imagery shows the mid level shortwave currently bringing rain showers and isolated thunderstorms to the region exiting into Illinois this afternoon. This will lead to showers and storms in northwest Illinois slowly exiting the area through late afternoon.

High pressure is forecast to build into the area behind this system with quiet weather forecast tonight through Saturday afternoon. Low temperatures Friday night are forecast to be in the mid to upper 50s with high temperatures Saturday in the lower 80s.

LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/

Issued at 210 PM CDT Fri Jun 26 2026

Saturday night, a shortwave is forecast to move across the area with a warm front draped along a roughly Fairfield to Macomb line. Ahead of the shortwave that is forecast to move across the area after 06 UTC Sunday, a 20 knots low level jet is forecast to develop and lead to scattered shower and thunderstorm development across the area. Most unstable cape values of 1000 to 2000 J/KG are forecast with around 30 knots of deep layer shear. There is a a Marginal (Level 1 out of 5) Risk of severe storms along and south of a line from Fairfield to Macomb. The main risks will be hail and gusty winds. Rainfall amounts will be light.

Showers and storms may linger into Sunday morning with cloud cover across the area as the warm front exits into Minnesota and Wisconsin. This will be the beginning of a pattern change that is forecast to continue through next week. High temperatures on Sunday will be around 90 degrees with dewpoints in the lower to mid 70s across the area. There will also be a tight pressure gradient across the CWA with breezy conditions and potential for gusts of 25 to 30 MPH. Heat indices on Sunday may hover around 100 degrees during the afternoon especially in southeast Iowa, northeast Missouri, and adjacent west central Illinois but this will also depend on lingering cloud cover.

Ridging at 500 MB will sit across the area for much of next week with some differences in the placement of the ridge axis. There continues to be increasing confidence in hot and humid conditions next week with high temperatures in the lower to mid 90s each day and dew points in the lower to mid 70s. Heat index values of 100+ are forecast each day. Decided to hold off on a heat watch for this forecast issuance at this time but one will be needed due to both the forecast heat indices and duration of the heat and humidity next week. The main question will be if the storm track is closer to the area and if any convection causes clouds to spread over the area each day limiting the heating across the area and keeping heat indices below 100.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 618 PM CDT Fri Jun 26 2026

Prior to the period, a storm system exited the region. This has left behind a BKN to OVC MVFR deck at BRL/MLI. MVFR CIGs are expected to continue through 14-15Z at BRL/MLI, with BRL falling into IFR CIGs by 27/02Z due to saturated to near-saturated low level air. CID is at the northern edge of these cloud decks, so a northward shift in the deck could lead to BKN MVFR CIGs from 04-14Z, rather than SCT. Otherwise, light easterly winds are expected to continue through the period.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.